This invention relates to fluid reclamation devices which are used with engines using lubricating oils and hydraulic systems to remove solid contaminates and water or other volatile contaminates from the lubricating oils or hydraulic fluids. More particularly, the invention relates to a unique evaporation plate construction and an improved screw on filter assembly.
Oil reclamation devices of the general type disclosed and described herein are generally well known. These devices are used to remove both solid and liquid contaminates from the lubricating oil. It is well known that oil in and of itself does not "wear out" and that additives contained in the oil remain relatively stable once a predetermined level has been reached. Once the solid and volatile contaminates are removed from the oil, the oil is substantially reconditioned and remains in a useful state.
A discussion of oil reclamation devices is found in U.S. Department of Energy publication DOE/BC/10256-1 Initial Assessment of Selected Advanced Lubricating Oil Filter, September 1981. As part of the publication, patent and literature searches were conducted. Fifty seven patents were listed which showed filters that extract vapor from oil under vacuum and/or with added heat along with seventeen literature references.
Pertinent prior art which is specifically directed towards oil reclamation devices of the general construction of the present invention are typified by the U.S. Pat. Nos. 4,289,583, 4,227,969, 4,189,351 and 4,943,352.
U.S. Pat. No. 4,289,583 discloses an oil reclamation device with a cap heating head having a heat transmitting member mounted in a cavity and an evaporator plate mounted to the cap heating head to form a baffled evaporator chamber. The filter housing contains the evaporator plate and is secured to the cap heating head. The filter housing is provided with an oil inlet valve at its bottom.
U.S. Pat. Nos. 4,227,969 and 4,189,351 disclose oil reclamation devices of a similar construction, both having a fixed filter and oil inlet positioned in the base of the filter which requires piping from the engine or fluid source to disburse oil upward into the filter.
It is known in the art to utilize removable filters in connection with heated oil refining apparatus to remove liquid and solid contaminates from the oil used in internal combustion engines.
As an example in U.S. Pat. No. 4,146,475 the fine filter and coarse filter which are used in the apparatus can be replaced by separating them from the concentric cylinder housing by unscrewing the concentric cylinder housing.
In U.S. Pat. No. 4,585,924 a spin on diesel oil filter is used. The filter is constructed of conventional pleated paper construction with a base plate having a central threaded bore. The filter is screwed onto the lower threaded end of a nipple on an associated spacer which is in turn threaded at its top and screwed onto a second externally threaded nipple that is cast in and extends from the manifold.
In U.S. Pat. No. 4,943,352 a screwed on filter cartridge is fastened onto a nipple of an evaporator head with the cap member holding a heating element which is used to heat the evaporation chamber. A throughgoing tube is secured in the filter cartridge to deposit oil at the bottom of the filter.
In U.S. Pat. No. 4,369,110 the filter cartridge is provided with a perforated web having a central internal threaded opening which is screwed onto the outside of the end of a coaxial pipe which serves as an oil inlet and conduit. A needle member is screwed to the inside of the coaxial pipe and is jammed into the filter media providing a passageway for the oil into the filter cartridge.
The following patents also disclose the general state of the filter refining art: U.S. Pat. Nos. 4,388,185; 4,354,946; 4,249,438; 4,272,371; 4,261,838; 3,912,631 and 2,707,051.
Numerous disadvantages are associated with these known devices. For example, oil flows directly at a fairly high flow rate into a specific area of filter without dispersal throughout the filter container causing filter clogging and an increase in the micro size of the particles that are able to be filtered. Oil containing unvolitized contaminates will pass from the filter directly out of the oil outlet means of the container because it will not be included in any thin film traveling over the vaporizing surface on the upper side of the evaporator plate.
It is important that the oil passing across the vaporizing surface be maintained in a thin film to promote vaporization of the liquid contaminates. With other known filter refining devices, if the longitudinal axis is angularly disposed from the vertical while installed, the oil will all flow to one side of the evaporator plate.
None of the prior art devices are designed to effect the greatest efficiency of removing the contaminates and maintaining the operation of the device. Pressure build-up causes oil flow problems and shifting of the filter medium during operation. Inefficient transfer of heat from the heating surface to the thin film of oil is encountered because of spacing problems in the heater cavity and lack of heat conduction.
Another object of the invention is to provide a removable filter cartridge in an oil reclamation device which results in a high filtered oil flow.
A further object of the invention is to provide an evaporator plate with a heat transmitting member which contributes to establish a uniformity in heating and fluid flow through the evaporation chamber.
It is a further object of this invention to provide a filter assembly which will obviate problems associated with the disposition of fibrous material in the filter as it is provided in prior art oil reclamation devices.